Wind power is considered one of the cleanest, most environmentally friendly energy sources presently available, and wind turbines have gained increased attention in this regard. A modern wind turbine typically includes a tower, a nacelle mounted on the tower, a generator positioned in the nacelle, and one or more rotor blades. The one or more rotor blades convert kinetic energy of wind into mechanical energy using known airfoil principles. A drivetrain transmits the mechanical energy from the rotor blades to the generator. The generator then converts the mechanical energy to electrical energy that may be supplied to a utility grid.
The drivetrain may include a rotor shaft, a gearbox, and a generator shaft. More specifically, the rotor shaft may rotatably couple the rotor blades to the gearbox. The generator shaft may rotatably couple the gearbox to the generator. In this respect, the rotor blades may cause the rotor shaft to rotate. The rotation of the rotor shaft, in turn, drives the gearbox, generator shaft, and the generator.
Various sensors may be used to determine an estimated rotational position of the rotor shaft or other rotating components of the drivetrain. For example, a position sensor, such as an incremental or absolute encoder, may generate a signal associated with the position of the rotor shaft. The position sensor, however, may not be aligned with the phase of the rotor shaft, thereby providing an inaccurate estimation of the rotor shaft position. For example, the position sensor is not aligned with the correct phase of the rotor shaft if the position sensor is operatively coupled to the generator shaft. Furthermore, even if the position sensor is operatively coupled to the rotor shaft, the position sensor may easily be misaligned with the phase of the rotor shaft during installation. Alternatively, accelerometers may also be used to estimate the position of the rotor shaft. The signals generated by the accelerometers may, however, include significant noise, which may result in relatively inaccurate estimations of the rotor shaft position.
Accordingly, improved wind turbines, and, in particular, improved systems and methods for determining the estimated position of the rotor shaft of the wind turbine, are desired in the art. Specifically, systems and methods that produce relatively more accurate estimations of the position of the rotor shaft of the wind turbine would be advantageous.